Perivalvular leakage (PVL) is a complication that is related to the replacement of heart valves. It occurs when blood flows through a channel or gap between the structure of an implanted valve and the cardiac or arterial tissue due to a lack of appropriate sealing.
Intimate apposition of replacement heart valves and the surrounding cardiac or arterial walls seals the valve and minimizes PVL. In certain cases, however, a seal cannot be achieved, leaving irregular gaps of different sizes and shapes between the valve and the cardiac or arterial walls. This may result from inadequate sizing, incomplete expansion of the valve, an irregularly deformed valve, or highly eccentric or irregular calcification pattern on the leaflets or valve annulus.
PVL has been shown to greatly affect the clinical outcome of transcatheter aortic valve replacement procedures, and the severity of perivalvular leakage has been correlated with patient mortality. What is therefore needed is a replacement bioprosthetic heart valve which permits a conforming engagement or fit with the surrounding cardiac or arterial wall so as to substantially fill in the gaps or channels that often result in PVL.